{
    // 数组的索引签名
    type myArray<T> = {
        [index: number]: T
    }
    const arr: myArray<string> = ['ck', '安徽国防科技学院']
}

{

    // 对象的索引签名
    type map = {
        [x: string | number | symbol]: any
    }

    const user: map = {
        name: "ck",
        age: 18
    }

    // 数组的索引签名
    type Arr<T extends any> = T[];

    const arr:Arr<string> = ['name', 'is', 'ck']

}